Comparative analysis of secondary structure of 5.8S-ITS2 rRNA in the genus Usnea
松萝属的5.8S-ITS2二级结构比较分析

The secondary structure of 5.8S rRNA and ITS2 of Usnea (Parmeliaceae) was investigated and a secondary structure model for this group of lichens was proposed. Structure variations among species were mainly located in the helixes of ITS2 and different types of helixes in ITS2 were recognized. Length variations of these domains seemed to be species-specific. The phylogenetic relationships among species of Usnea based on nucleotide comparison was identical with those inferred from secondary structure characters, which suggests that the structure information could be used as an additional taxonomic character for species identification and phylogenetic implication of Usnea.